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The effects of different spectral compositions of light-emitting diode (LED) sources and fertilizer containing biologically active silicon (Si) in the nutrient solution on morphological and physiological plant response were studied. Qualitative indicators and the productivity of plants of a red-leaved and a green-leaved lettuce were estimated. Lettuce was grown applying low-volume hydroponics in closed artificial agroecosystems. The positive effect of Si fertilizer used as a microadditive in the nutrient solution on the freshly harvested biomass was established on the thirtieth day of vegetation under LEDs. Increase in productivity of the red-leaved lettuce for freshly harvested biomass was 26.6%, while for the green-leaved lettuce no loss of dry matter was observed. However, being grown under sodium lamps, a negative impact of Si fertilizer on productivity of both types of plants was observed: the amount of harvested biomass decreased by 22.6% and 30.3% for the green- and red-leaved lettuces, respectively. The effect of using Si fertilizer dramatically changed during the total growing period: up to the fifteenth day of cultivation, a sharp inhibition of the growth of both types of lettuce was observed; then, by the thirtieth day of LED lighting, Si fertilizer showed a stress-protective effect and had a positive influence on the plants. However, by the period of ripening there was no effect of using the fertilizer. Therefore, we can conclude that the use of Si fertilizers is preferable only when LED irradiation is applied throughout the active plant growth period.
Natalya Semenova; Alexandr Smirnov; Andrey Grishin; Roman Pishchalnikov; Denis Chesalin; Sergey Gudkov; Narek Chilingaryan; Anastasia Skorokhodova; Alexey Dorokhov; Andrey Izmailov. The Effect of Plant Growth Compensation by Adding Silicon-Containing Fertilizer under Light Stress Conditions. Plants 2021, 10, 1287 .
AMA StyleNatalya Semenova, Alexandr Smirnov, Andrey Grishin, Roman Pishchalnikov, Denis Chesalin, Sergey Gudkov, Narek Chilingaryan, Anastasia Skorokhodova, Alexey Dorokhov, Andrey Izmailov. The Effect of Plant Growth Compensation by Adding Silicon-Containing Fertilizer under Light Stress Conditions. Plants. 2021; 10 (7):1287.
Chicago/Turabian StyleNatalya Semenova; Alexandr Smirnov; Andrey Grishin; Roman Pishchalnikov; Denis Chesalin; Sergey Gudkov; Narek Chilingaryan; Anastasia Skorokhodova; Alexey Dorokhov; Andrey Izmailov. 2021. "The Effect of Plant Growth Compensation by Adding Silicon-Containing Fertilizer under Light Stress Conditions." Plants 10, no. 7: 1287.
Variation potential (VP) is an important long-distance electrical signal in higher plants that is induced by local damages, influences numerous physiological processes, and participates in plant adaptation to stressors. The transmission of increased hydraulic pressure through xylem vessels is the probable mechanism of VP propagation in plants; however, the rates of the pressure transmission and VP propagation can strongly vary. We analyzed this problem on the basis of a simple mathematical model of the pressure distribution along a xylem vessel, which was approximated by a tube with a pressure gradient. It is assumed that the VP is initiated if the integral over pressure is more than a threshold one, taking into account that the pressure is transiently increased in the initial point of the tube and is kept constant in the terminal point. It was shown that this simple model can well describe the parameters of VP propagation in higher plants, including the increase in time before VP initiation and the decrease in the rate of VP propagation with an increase in the distance from the zone of damage. Considering three types of the pressure dynamics, our model predicts that the velocity of VP propagation can be stimulated by an increase in the length of a plant shoot and also depends on pressure dynamics in the damaged zone. Our results theoretically support the hypothesis about the impact of pressure variations in xylem vessels on VP propagation.
Ekaterina Sukhova; Elena Akinchits; Sergey Gudkov; Roman Pishchalnikov; Vladimir Vodeneev; Vladimir Sukhov. A Theoretical Analysis of Relations between Pressure Changes along Xylem Vessels and Propagation of Variation Potential in Higher Plants. Plants 2021, 10, 372 .
AMA StyleEkaterina Sukhova, Elena Akinchits, Sergey Gudkov, Roman Pishchalnikov, Vladimir Vodeneev, Vladimir Sukhov. A Theoretical Analysis of Relations between Pressure Changes along Xylem Vessels and Propagation of Variation Potential in Higher Plants. Plants. 2021; 10 (2):372.
Chicago/Turabian StyleEkaterina Sukhova; Elena Akinchits; Sergey Gudkov; Roman Pishchalnikov; Vladimir Vodeneev; Vladimir Sukhov. 2021. "A Theoretical Analysis of Relations between Pressure Changes along Xylem Vessels and Propagation of Variation Potential in Higher Plants." Plants 10, no. 2: 372.
The funding statement in the first sentence of the Acknowledgements section in the original publication is incorrect. The corrected Acknowledgements section is printed below.
Roman Y. Pishchalnikov; Vladimir V. Shubin; Andrei. P. Razjivin. Correction to: The role of vibronic modes in formation of red antenna states of cyanobacterial PSI. Photosynthesis Research 2020, 147, 241 -241.
AMA StyleRoman Y. Pishchalnikov, Vladimir V. Shubin, Andrei. P. Razjivin. Correction to: The role of vibronic modes in formation of red antenna states of cyanobacterial PSI. Photosynthesis Research. 2020; 147 (2):241-241.
Chicago/Turabian StyleRoman Y. Pishchalnikov; Vladimir V. Shubin; Andrei. P. Razjivin. 2020. "Correction to: The role of vibronic modes in formation of red antenna states of cyanobacterial PSI." Photosynthesis Research 147, no. 2: 241-241.
Cyanobacterial photosystem I (PSI) constitutes monomeric and trimeric pigment–protein complexes whose optical properties are marked by the presence of long-wavelength absorption bands. In spite of numerous experimental studies, the nature of these bands is still under debate and requires intensive theoretical analysis. Collecting together the data of linear spectroscopy and single-molecule spectroscopy (SMS) of PSI from Arthrospira platensis, we performed quantum modeling of the optical response based on molecular exciton theory (ET) and the multimode Brownian oscillator model (MBOM). Applying MBOM, the spectra of the red antenna state were calculated considering a particular for each red state adjustment of the low-frequency vibronic modes. Within the framework of our PSI exciton model it was shown that the coupling energy between antenna chlorophylls cannot be a factor of the red states formation, thus the long-wavelength bands are calculated without attribution to so-called antenna red chlorophylls. By the fitting of Huang–Rhys factors and frequencies for the lowest vibronic modes, we were able to reproduce the effects of strong and weak electron–phonon coupling experimentally observed in SMS spectra of red antenna states. Based on our theoretical calculations and also analysis of existing crystal structures of cyanobacterial PSI, we assumed that long-wavelength Chls can be localized in the peripheral protein subunits containing one or two pigment molecules.
Roman Y. Pishchalnikov; Vladimir. V. Shubin; Andrei. P. Razjivin. The role of vibronic modes in formation of red antenna states of cyanobacterial PSI. Photosynthesis Research 2020, 146, 75 -86.
AMA StyleRoman Y. Pishchalnikov, Vladimir. V. Shubin, Andrei. P. Razjivin. The role of vibronic modes in formation of red antenna states of cyanobacterial PSI. Photosynthesis Research. 2020; 146 (1-3):75-86.
Chicago/Turabian StyleRoman Y. Pishchalnikov; Vladimir. V. Shubin; Andrei. P. Razjivin. 2020. "The role of vibronic modes in formation of red antenna states of cyanobacterial PSI." Photosynthesis Research 146, no. 1-3: 75-86.
Linear optical response of the orange carotenoid protein (OCP) and its mutants was successfully simulated by applying the Differential evolution (DE) algorithm. OCP is a pigment-protein complex, which plays an important role in non-photochemical quenching of excitation energy in photosynthetic light-harvesting complexes in cyanobacteria. It contains a single carotenoid pigment molecule surrounded by protein matrix. This pigment is entirely responsible for OCP absorption in the region of 350–600 nm. To calculate the OCP absorption spectra, we used the Multimode Brownian oscillator model considering four high vibronic modes (\( \upnu_{1} \), \( \upnu_{2} \), \( \upnu_{3} \) and \( \upnu_{4} \)) and one low frequency mode. The frequencies of these modes were estimated from the OCP Raman spectra; whereas the Huang-Rhys factors alongside the carotenoid electronic transition and the FWHM of inhomogeneous broadening and the low frequency mode were fitted by DE. It was show that characteristic features of OCP absorption spectra can be explained by mutual variations of Huang-Rhys factors of \( \upnu_{1} \) and \( \upnu_{2} \) that is corresponded to the in-phase stretching of C = C and C-C bonds.
Roman Pishchalnikov; Igor Yaroshevich; Eugene Maksimov; Nikolai Sluchanko; Alexey Stepanov; David Buhrke; Thomas Friedrich. Orange Carotenoid Protein Absorption Spectra Simulation Using the Differential Evolution Algorithm. Communications in Computer and Information Science 2019, 302 -312.
AMA StyleRoman Pishchalnikov, Igor Yaroshevich, Eugene Maksimov, Nikolai Sluchanko, Alexey Stepanov, David Buhrke, Thomas Friedrich. Orange Carotenoid Protein Absorption Spectra Simulation Using the Differential Evolution Algorithm. Communications in Computer and Information Science. 2019; ():302-312.
Chicago/Turabian StyleRoman Pishchalnikov; Igor Yaroshevich; Eugene Maksimov; Nikolai Sluchanko; Alexey Stepanov; David Buhrke; Thomas Friedrich. 2019. "Orange Carotenoid Protein Absorption Spectra Simulation Using the Differential Evolution Algorithm." Communications in Computer and Information Science , no. : 302-312.
Comparative study of spectroscopic features reveals the structural determinants of keto-carotenoids in photoactive water-soluble proteins.
Roman Y. Pishchalnikov; Igor A. Yaroshevich; Tatiana A. Slastnikova; Aleksandr A. Ashikhmin; Alexey V. Stepanov; Ekaterina A. Slutskaya; Thomas Friedrich; Nikolai N. Sluchanko; Eugene G. Maksimov. Structural peculiarities of keto-carotenoids in water-soluble proteins revealed by simulation of linear absorption. Physical Chemistry Chemical Physics 2019, 21, 25707 -25719.
AMA StyleRoman Y. Pishchalnikov, Igor A. Yaroshevich, Tatiana A. Slastnikova, Aleksandr A. Ashikhmin, Alexey V. Stepanov, Ekaterina A. Slutskaya, Thomas Friedrich, Nikolai N. Sluchanko, Eugene G. Maksimov. Structural peculiarities of keto-carotenoids in water-soluble proteins revealed by simulation of linear absorption. Physical Chemistry Chemical Physics. 2019; 21 (46):25707-25719.
Chicago/Turabian StyleRoman Y. Pishchalnikov; Igor A. Yaroshevich; Tatiana A. Slastnikova; Aleksandr A. Ashikhmin; Alexey V. Stepanov; Ekaterina A. Slutskaya; Thomas Friedrich; Nikolai N. Sluchanko; Eugene G. Maksimov. 2019. "Structural peculiarities of keto-carotenoids in water-soluble proteins revealed by simulation of linear absorption." Physical Chemistry Chemical Physics 21, no. 46: 25707-25719.
We report the results of a physiological study that include ECG analysis, capillary blood velocity (CBV) data, and blood pressure (BP) measurements obtained under conditions of modified external magnetic field (MF). Each of eight volunteers was sequentially exposed to MFs of three different types for 22 h. A Helmholtz-like MF exposure system was used. The system was specially designed for long-term exposures of human beings to static and low frequency MFs. The MF of the first type reproduced an initially recorded geomagnetic storm (GS). The MF inductions of the other two types were about 55 and 49 μT, which corresponded to the natural local magnetic background and a slightly decreased MF, respectively. In all three cases, the environmental magnetic fluctuations were suppressed by the active Helmholtz system. The variability of RR intervals was considered as a key indicator of cardiovascular response to the MFs and weather conditions. A time-frequency representation (TFR) and a frequency-frequency representation (FFR) were used for processing of the time series of RR intervals. It turned out that the transformation to TFR makes it possible to obtain the characteristic matrix of RR intervals; such a matrix can be used as a subject identifier. FFR was used to calculate correlations of RR intervals with the components of the MFs. The averaged correlation coefficients of RR intervals with the Bx and By components appeared significantly higher (p < 0.001) during the Storm mode in comparison with control. Thus, it is shown that artificial geomagnetic storm can cause a detectable cardiovascular response.
R.Y. Pishchalnikov; Y.I. Gurfinkel; R.M. Sarimov; A.L. Vasin; M.L. Sasonko; T.A. Matveeva; V.N. Binhi; M.V. Baranov. Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather. Biomedical Signal Processing and Control 2019, 51, 401 -410.
AMA StyleR.Y. Pishchalnikov, Y.I. Gurfinkel, R.M. Sarimov, A.L. Vasin, M.L. Sasonko, T.A. Matveeva, V.N. Binhi, M.V. Baranov. Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather. Biomedical Signal Processing and Control. 2019; 51 ():401-410.
Chicago/Turabian StyleR.Y. Pishchalnikov; Y.I. Gurfinkel; R.M. Sarimov; A.L. Vasin; M.L. Sasonko; T.A. Matveeva; V.N. Binhi; M.V. Baranov. 2019. "Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather." Biomedical Signal Processing and Control 51, no. : 401-410.
Based on single molecule spectroscopy analysis and our preliminary theoretical studies, the linear and fluorescence spectra of the PSI trimer from Arthrospira platensis with different realizations of the static disorder were modeled at cryogenic temperature. Considering the previously calculated spectral density of chlorophyll, an exciton model for the PSI monomer and trimer including the red antenna states was developed taking into account the supposed similarity of PSI antenna structures from Thermosynechococcus e., Synechocystis sp. PCC6803, and Arthrospira platensis. The red Chls in the PSI monomer were assumed to be in the nearest proximity of the reaction center. The PSI trimer model allowed the simulation of experimentally measured zero phonon line distribution of the red states considering a weak electron-phonon coupling for the antenna exciton states. However, the broad absorption and fluorescence spectra of an individual emitter at 760 nm were calculated by adjusting the Huang-Rhys factors of the chlorophyll lower phonon modes assuming strong electron-phonon coupling.
Roman Pishchalnikov; Vladimir Shubin; Andrei Razjivin. Single Molecule Fluorescence Spectroscopy of PSI Trimers from Arthrospira platensis: A Computational Approach. Molecules 2019, 24, 822 .
AMA StyleRoman Pishchalnikov, Vladimir Shubin, Andrei Razjivin. Single Molecule Fluorescence Spectroscopy of PSI Trimers from Arthrospira platensis: A Computational Approach. Molecules. 2019; 24 (4):822.
Chicago/Turabian StyleRoman Pishchalnikov; Vladimir Shubin; Andrei Razjivin. 2019. "Single Molecule Fluorescence Spectroscopy of PSI Trimers from Arthrospira platensis: A Computational Approach." Molecules 24, no. 4: 822.
For many applications the Differential Evolution (DE) algorithm had proved to be a very efficient tool for getting the best solution especially when the problem has hundreds of free parameters to optimize. This study aims to expend the list of DE successful scientific applications and to use the DE method for photosynthetic pigments optical response modelling. Chlorophyll (Chl) and bacteriochlorophyll (BChl) are the main pigment molecules of the photosynthetic light-harvesting complexes. These complexes are responsible for photon absorption and sequential transport of energy to the photosynthetic reaction center where the charge separation occurs. The DE routines were adopted to perform the fitting of Chl and Bchl Qy band absorption and fluorescence spectra measured in dimethyl ether. To simulate these spectra the stochastic Brownian oscillator model with 49 vibronic modes for Chl and 60 modes for BChl has been applied. By using the artificially calculated spectra, 10 strategies were tested with different settings of the scaling factor (F) and crossover parameter (Cr) before to fit the real experimental data. Once the proper strategy and settings, which give the fastest convergence, were found, the set of parameters representing the electron-phonon coupling (Huang–Rhys factors) and the lowest frequency modes were calculated. These parameters can be used for modelling of the light-harvesting complex nonlinear optical response.
Roman Pishchalnikov. Application of the differential evolution for simulation of the linear optical response of photosynthetic pigments. Journal of Computational Physics 2018, 372, 603 -615.
AMA StyleRoman Pishchalnikov. Application of the differential evolution for simulation of the linear optical response of photosynthetic pigments. Journal of Computational Physics. 2018; 372 ():603-615.
Chicago/Turabian StyleRoman Pishchalnikov. 2018. "Application of the differential evolution for simulation of the linear optical response of photosynthetic pigments." Journal of Computational Physics 372, no. : 603-615.
Yury Gurfinkel; Mikhail Baranov; Andrey Vasin; Roman Pishchalnikov. Evaluation of combined effects of lunar gravity simulation and the altered magnetic field on cardiovascular system of healthy volunteers. Frontiers in Physiology 2018, 9, 1 .
AMA StyleYury Gurfinkel, Mikhail Baranov, Andrey Vasin, Roman Pishchalnikov. Evaluation of combined effects of lunar gravity simulation and the altered magnetic field on cardiovascular system of healthy volunteers. Frontiers in Physiology. 2018; 9 ():1.
Chicago/Turabian StyleYury Gurfinkel; Mikhail Baranov; Andrey Vasin; Roman Pishchalnikov. 2018. "Evaluation of combined effects of lunar gravity simulation and the altered magnetic field on cardiovascular system of healthy volunteers." Frontiers in Physiology 9, no. : 1.
The influence of the previously recorded geomagnetic storm (GS) on human cardiovascular system and microcirculation has been studied under laboratory conditions. Healthy volunteers in lying position were exposed under two artificially created conditions: quiet (Q) and storm (S). The Q regime playbacks a noise-free magnetic field (MF) which is closed to the natural geomagnetic conditions on Moscow's latitude. The S regime playbacks the initially recorded 6-h geomagnetic storm which is repeated four times sequentially. The cardiovascular response to the GS impact was assessed by measuring capillary blood velocity (CBV) and blood pressure (BP) and by the analysis of the 24-h ECG recording. A storm-to-quiet ratio for the cardio intervals (CI) and the heart rate variability (HRV) was introduced in order to reveal the average over group significant differences of HRV. An individual sensitivity to the GS was estimated using the autocorrelation function analysis of the high-frequency (HF) part of the CI spectrum. The autocorrelation analysis allowed for detection a group of subjects of study which autocorrelation functions (ACF) react differently in the Q and S regimes of exposure.
Yu I. Gurfinkel; A. L. Vasin; R. Yu Pishchalnikov; R. M. Sarimov; M. L. Sasonko; T. A. Matveeva. Geomagnetic storm under laboratory conditions: randomized experiment. International Journal of Biometeorology 2017, 62, 501 -512.
AMA StyleYu I. Gurfinkel, A. L. Vasin, R. Yu Pishchalnikov, R. M. Sarimov, M. L. Sasonko, T. A. Matveeva. Geomagnetic storm under laboratory conditions: randomized experiment. International Journal of Biometeorology. 2017; 62 (4):501-512.
Chicago/Turabian StyleYu I. Gurfinkel; A. L. Vasin; R. Yu Pishchalnikov; R. M. Sarimov; M. L. Sasonko; T. A. Matveeva. 2017. "Geomagnetic storm under laboratory conditions: randomized experiment." International Journal of Biometeorology 62, no. 4: 501-512.
The spatial position of the long-wavelength chlorophylls in trimer of pigment-protein complex of photosystem I (PSI) have been determined bymodeling the optical fluorescence absorption and emission spectra for two hypothetical models of PSI trimer. The calculation has been performed using X-ray diffraction data on the spatial position of chlorophylls in PSI monomer; the pigment site energies were taken from the studies of other researchers, while interactions between monomers in trimer are considered as fitting parameters. The interaction energy between the chlorophylls spaced by a distance smaller than 10 Å was estimated based on the concept of extended dipole−dipole interaction. The model under study allowed us to evaluate the influence of the exciton interaction between peripheral pigments on the optical response of PSI trimer. The intensity and shape of stationary fluorescence line turned out to be sensitive to the PSI monomer packing in trimer. A visualization of the density matrix for low-energy exciton states has made it possible to estimate the localization of long-wavelength chlorophylls in PSI trimer.
R. Yu. Pishchalnikov; V. V. Shubin; A. P. Razjivin. Spectral differences between monomers and trimers of photosystem I depend on the interaction between peripheral chlorophylls of neighboring monomers in trimer. Physics of Wave Phenomena 2017, 25, 185 -195.
AMA StyleR. Yu. Pishchalnikov, V. V. Shubin, A. P. Razjivin. Spectral differences between monomers and trimers of photosystem I depend on the interaction between peripheral chlorophylls of neighboring monomers in trimer. Physics of Wave Phenomena. 2017; 25 (3):185-195.
Chicago/Turabian StyleR. Yu. Pishchalnikov; V. V. Shubin; A. P. Razjivin. 2017. "Spectral differences between monomers and trimers of photosystem I depend on the interaction between peripheral chlorophylls of neighboring monomers in trimer." Physics of Wave Phenomena 25, no. 3: 185-195.
The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling “ARFA” has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.
Yu.I. Gurfinkel; O.Yu. At'Kov; A.L. Vasin; T.K. Breus; M.L. Sasonko; R.Yu. Pishchalnikov. Effect of zero magnetic field on cardiovascular system and microcirculation. Life Sciences in Space Research 2016, 8, 1 -7.
AMA StyleYu.I. Gurfinkel, O.Yu. At'Kov, A.L. Vasin, T.K. Breus, M.L. Sasonko, R.Yu. Pishchalnikov. Effect of zero magnetic field on cardiovascular system and microcirculation. Life Sciences in Space Research. 2016; 8 ():1-7.
Chicago/Turabian StyleYu.I. Gurfinkel; O.Yu. At'Kov; A.L. Vasin; T.K. Breus; M.L. Sasonko; R.Yu. Pishchalnikov. 2016. "Effect of zero magnetic field on cardiovascular system and microcirculation." Life Sciences in Space Research 8, no. : 1-7.
A short description of two theories of the primary photosynthetic processes is given. Generally accepted in 1950s–1990s, the localized excited states theory has been changed to the modern exciton theory. Appearance of the new experimental data and the light-harvesting complex crystal structure are reasons why the exciton theory has become important. The bulk of data for the old theory and outstanding experiments that have been the driving force for a new theory are discussed in detail.
R. Y. Pishchalnikov; A. P. Razjivin. From localized excited states to excitons: Changing of conceptions of primary photosynthetic processes in the twentieth century. Biochemistry (Moscow) 2014, 79, 242 -250.
AMA StyleR. Y. Pishchalnikov, A. P. Razjivin. From localized excited states to excitons: Changing of conceptions of primary photosynthetic processes in the twentieth century. Biochemistry (Moscow). 2014; 79 (3):242-250.
Chicago/Turabian StyleR. Y. Pishchalnikov; A. P. Razjivin. 2014. "From localized excited states to excitons: Changing of conceptions of primary photosynthetic processes in the twentieth century." Biochemistry (Moscow) 79, no. 3: 242-250.
Dmitriy Shevela; Roman Pishchalnikov; Lutz Eichacker. Oxygenic Photosynthesis in Cyanobacteria. Stress Biology of Cyanobacteria 2013, 3 -40.
AMA StyleDmitriy Shevela, Roman Pishchalnikov, Lutz Eichacker. Oxygenic Photosynthesis in Cyanobacteria. Stress Biology of Cyanobacteria. 2013; ():3-40.
Chicago/Turabian StyleDmitriy Shevela; Roman Pishchalnikov; Lutz Eichacker. 2013. "Oxygenic Photosynthesis in Cyanobacteria." Stress Biology of Cyanobacteria , no. : 3-40.
We have proposed a mechanism of coherent modulations of the P* state in the transient absorption spectra of the reaction centers isolated from purple bacteria. Two water molecules, located between special pair, Ba, Bb chlorophylls and histidine L175 and M202, are supposed to be the ortho-H2O and para-H2O isomers with different magnetic properties. The distinctive modulation frequencies were labeled as rotational resonances of the ortho-H2O. According to our assumption, the interaction of rotational modes of water isomers with the charge transfer states is a reason of coherent modulations of kinetics. We have modified the system Hamiltonian in order to take into account the rotational modes of ortho-H2O. Evolution of the density matrix was calculated in the Liouville space. The relaxation Redfield theory for molecular aggregates was used to model kinetics up to 3 ps.
R. Yu. Pishchalnikov; S. M. Pershin; A. F. Bunkin. Quantum differences of ortho/para H2O spin-isomers as a factor of the femtosecond charge separation kinetics modulation in the reaction center of purple bacteria. Biophysics 2012, 57, 779 -785.
AMA StyleR. Yu. Pishchalnikov, S. M. Pershin, A. F. Bunkin. Quantum differences of ortho/para H2O spin-isomers as a factor of the femtosecond charge separation kinetics modulation in the reaction center of purple bacteria. Biophysics. 2012; 57 (6):779-785.
Chicago/Turabian StyleR. Yu. Pishchalnikov; S. M. Pershin; A. F. Bunkin. 2012. "Quantum differences of ortho/para H2O spin-isomers as a factor of the femtosecond charge separation kinetics modulation in the reaction center of purple bacteria." Biophysics 57, no. 6: 779-785.
The dynamics of charge separation states has been numerically simulated in order to calculate the polarization (in the third order of the perturbation theory) and its evolution in a pulsed optical field. Time evolution of the rotational states of the ortho-D2O isomer with a nonzero magnetic momentum and mixed ortho/para-D2O states have been calculated on the basis of the Liouville equation for the density matrix and the Redfield relaxation model for molecular aggregates. Frequencies similar to the known experimental frequencies of the modulation of the kinetics (electron transfer) of the reaction centers special pair in purple bacteria are selected from the set of calculated rotational-resonance frequencies. This semiquantitative coincidence of frequencies (within the experimental error) confirms the previously stated hypothesis, according to which the ortho-H2O (D2O) spin isomer can play a role of mediator during electron transfer in the reaction centers of purple bacteria.
R. Yu. Pishchalnikov; S. M. Pershin; A. F. Bunkin. H2O and D2O spin-isomers as a mediator of the electron transfer in the reaction center of purple bacteria. Physics of Wave Phenomena 2012, 20, 184 -192.
AMA StyleR. Yu. Pishchalnikov, S. M. Pershin, A. F. Bunkin. H2O and D2O spin-isomers as a mediator of the electron transfer in the reaction center of purple bacteria. Physics of Wave Phenomena. 2012; 20 (3):184-192.
Chicago/Turabian StyleR. Yu. Pishchalnikov; S. M. Pershin; A. F. Bunkin. 2012. "H2O and D2O spin-isomers as a mediator of the electron transfer in the reaction center of purple bacteria." Physics of Wave Phenomena 20, no. 3: 184-192.
S. M. Pershin; R. Yu. Pishchalnikov. Spectroscopic evidence for the effect of the ortho H2O spin on the electron transfer in photosynthesis. Physics of Wave Phenomena 2012, 20, 35 -44.
AMA StyleS. M. Pershin, R. Yu. Pishchalnikov. Spectroscopic evidence for the effect of the ortho H2O spin on the electron transfer in photosynthesis. Physics of Wave Phenomena. 2012; 20 (1):35-44.
Chicago/Turabian StyleS. M. Pershin; R. Yu. Pishchalnikov. 2012. "Spectroscopic evidence for the effect of the ortho H2O spin on the electron transfer in photosynthesis." Physics of Wave Phenomena 20, no. 1: 35-44.
Two types of peripheral light-harvesting complexes LH2 (B800–850) from photosynthetic purple bacterium Allochromatium minutissimum were studied. First type containing carotenoids was prepared from wild type cells. The other one was obtained from carotenoid depleted cells grown with diphenylamine. We have shown that under laser femtosecond excitation within absorption 1200–1500 nm wavelength range the two-photon excitation of LH2 complexes takes place. This can be observed as fluorescence of bacteriochlorophyll (BChl) spectral form B850 (BChl molecules of circular aggregate with strong exciton interaction in 850 nm spectral domain). LH2 fluorescence excitation spectra under two-photon excitation are the same for carotenoid-containing and carotenoidless preparations. In both cases the broad band with peak near 1350 (675) nm (FWHM ∼ 240 (120) nm) was found. It is concluded that the broad band with peak near 1350 (675) nm in two-photon excitation spectra of LH2 complexes from Allochromatium minutissimum cannot be interpreted as two-photon excitation band of the optically forbidden S0 → S1 transition of carotenoids (rhodopin). Possible nature of this band is discussed.
I. A. Stepanenko; V. O. Kompanets; S. V. Chekalin; Z. K. Makhneva; A. A. Moskalenko; R. Yu. Pishchalnikov; A. P. Razjivin. Two-photon excitation spectrum of fluorescence of the light-harvesting complex B800–850 from Allochromatium minutissimum within 1200–1500 (600–750) nm spectral range is not carotenoid mediated. Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology 2009, 3, 116 -122.
AMA StyleI. A. Stepanenko, V. O. Kompanets, S. V. Chekalin, Z. K. Makhneva, A. A. Moskalenko, R. Yu. Pishchalnikov, A. P. Razjivin. Two-photon excitation spectrum of fluorescence of the light-harvesting complex B800–850 from Allochromatium minutissimum within 1200–1500 (600–750) nm spectral range is not carotenoid mediated. Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology. 2009; 3 (2):116-122.
Chicago/Turabian StyleI. A. Stepanenko; V. O. Kompanets; S. V. Chekalin; Z. K. Makhneva; A. A. Moskalenko; R. Yu. Pishchalnikov; A. P. Razjivin. 2009. "Two-photon excitation spectrum of fluorescence of the light-harvesting complex B800–850 from Allochromatium minutissimum within 1200–1500 (600–750) nm spectral range is not carotenoid mediated." Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology 3, no. 2: 116-122.
The transient absorption kinetics and spectra of isolated reaction centers of photosystem II (PSIIRC) have been modeled using modified Redfield theory. This yielded the site energies of the eight RC pigments, and the intrinsic charge separation rate as well as the charge recombination rate between the excited state and the first radical pair (RP) state. The intrinsic charge separation rate was found to be 0.67 ps−1 for the accessory chlorophyll on the D1 branch as primary electron donor. This is consistent with an average effective primary charge separation time of 5–6 ps. The site energies on the D1 and D2 branches were found asymmetric, with the site energies of all D2 branch pigments substantially higher than for the symmetrically equivalent D1 branch pigments. This is partially at variance with the results of other exciton modeling studies.
Roman Pishchalnikov; Marc G. Müller; Alfred R. Holzwarth. Theoretical Modeling of the Optical Properties and Exciton Dynamics of the PSII Reaction Center. Photosynthesis. Energy from the Sun 2008, 163 -166.
AMA StyleRoman Pishchalnikov, Marc G. Müller, Alfred R. Holzwarth. Theoretical Modeling of the Optical Properties and Exciton Dynamics of the PSII Reaction Center. Photosynthesis. Energy from the Sun. 2008; ():163-166.
Chicago/Turabian StyleRoman Pishchalnikov; Marc G. Müller; Alfred R. Holzwarth. 2008. "Theoretical Modeling of the Optical Properties and Exciton Dynamics of the PSII Reaction Center." Photosynthesis. Energy from the Sun , no. : 163-166.